I think you should do the following:
1) Assign private IP’s on all the servers (192.168.1.2, 192.168.1.3 …).
2) use the public IP’s in masquerade destination nat
iptables -t nat -A PREROUTING -p tcp -d 78.0.0.2 -j DNAT --to-destination 192.168.1.2
Should be ok now.
